X-Plain Pediatric Tuberculosis Reference Summary Introduction Tuberculosis, or TB, is a bacterial infection that causes more deaths in the world than any other infectious disease. When a child gets TB, it is called pediatric tuberculosis. 500,000 children around the world die from TB every year. Luckily, there is a treatment for tuberculosis. With treatment, 9 out of 10 kids with an active tuberculosis infection survive. Tuberculosis This reference summary is for parents of children with a diagnosis or possible diagnosis of tuberculosis. It explains latent and active tuberculosis infections. The program also discusses the diagnosis, treatment and prevention of tuberculosis. Causes Tuberculosis is an infection caused by a bacterium called Mycobacterium tuberculosis. The bacterium is also called tubercle bacillus. Tuberculosis spreads from person to person through air as a person with active tuberculosis coughs, sneezes, or expels air. After a child gets infected, the tuberculosis bacteria are controlled by his or her immune system. The infection becomes latent, or confined. When the bacteria spread out of control, the infection becomes active. 1
The immune system helps defend the body from viruses, bacteria, and foreign substances. It is made of blood cells and chemicals that find bacteria and viruses in the body and destroy them. Since an infected child only breathes out a few bacilli when he or she exhales, another person would have to be around the child for a month or more before they would catch tuberculosis. Adequate ventilation is the most important measure to prevent the transmission of tuberculosis. Tuberculosis is not usually transmitted through an infected child s personal things, like clothes, bedding or other items they have touched. Children are less likely than adults to transmit tuberculosis to others. Latent vs. Active Infection As a child breathes infected air, the bacilli go to the lungs through the bronchioles. At the end of the bronchioles are alveoli. Alveoli are balloon-like sacs where the blood takes oxygen from inhaled air and releases carbon dioxide into the air exhaled. Tuberculosis bacilli infect the alveoli. The body s immune system fights them. The immune system includes special blood cells that identify and destroy foreign material, including viruses and bacteria. These blood cells are called white blood cells. Special white blood cells called macrophages attack tuberculosis bacteria. Many of the bacteria die. Tuberculosis bacteria have a cell wall made of a complex waxy material. This wall protects some bacteria inside the macrophage! Tubercles Special cells of the immune system surround and separate the infected macrophages. The mass resulting from the separated, infected macrophages are hard, grayish nodules called tubercles. 2
Unfortunately, compared to adults, tuberculosis in children can spread to the blood and the rest of the body, including the brain, much sooner. Children with a weak immune system cannot fend off tuberculosis and are at a higher risk of having severe complications from the infection. Malnourished children as well as children with HIV/AIDS are in this category. When the bacilli spread to the lungs and others parts of the body, tuberculosis becomes active. If an infected child is healthy, the initial tuberculosis infection is controlled by the immune system. The tuberculosis bacilli may remain confined within the tubercles for years. This is called latent tuberculosis. Latent means dormant or sleeping. Most infected children heal completely after the initial infection. The tubercles calcify and the bacteria cannot break again. In a lot of infected children, the bacilli inside the tubercles become active later in life when their immune system becomes weak. This is called active tuberculosis. Tuberculosis in children is a big concern because it means they probably got it from an adult who may be transmitting the disease to others also. Most adults who develop active TB have been infected for years and it s just now becoming active. Symptoms Older babies and children usually have no signs or symptoms with the first infection of tuberculosis bacteria. There usually aren t even signs of infection on an x-ray! Once in a while, the child will have swollen lymph nodes or maybe some coughing. Tuberculosis can also cause a child to get meningitis and infections of the ears, kidneys, bones and joints. As the body s immune system kills the bad bacilli cells, good cells die as well. All these dead cells glob together and are called granulomas. Bacilli can survive but not grow in the granulomas. As more lung tissue dies and granulomas get bigger, cavities develop in the lungs. This allows lots of bacilli to spread when the child coughs. 3
As granulomas grow in the lungs, they may cause more coughing and shortness of breath as they destroy lung tissue. Granulomas can also eat away at blood vessels, causing bleeding in the lungs, which could result in bloody sputum. Symptoms of tuberculosis involving areas other than the lungs vary, depending on the organ affected. For example, when tuberculosis infects the spine, it can cause severe back pain or back deformities. Diagnosis Usually the only way to find out if a child has been exposed to TB is by giving a tuberculin skin test, or TST. The skin test is a simple test that feels like a bee sting. For a skin test, a substance called PPD is injected under the skin of the forearm. It has to be checked 48-72 hours later. If a red welt forms where the PPD was injected, the child may have tuberculosis, but it may not be active. Red welt Once in a while, the skin test is negative even though the child actually has tuberculosis. When this happens, it s usually because the child has a weak immune system. A blood test called QuantiFERON -TB can also show if a child has tuberculosis. To diagnose active tuberculosis, a doctor has to know about symptoms, whether the child has been exposed to TB and may need to take x-rays to check for TB infection. The only way to be sure if a child has an active TB infection is by a sputum test. The doctor will also take sputum and other samples for a pathologist to check. It is important to find out what type of tuberculosis bacteria a child has in order to prescribe the most effective medication. Sputum is another word for coughed out material that originates from the lungs. A pathologist is a doctor that mainly looks at samples under a microscope to find out more information about people s medical conditions or diseases. 4
Since it s difficult for a child to cough up sputum, the doctor may need to put a tube in the child s stomach to get some fluid out for testing. This is called a gastric aspirate. Treatment If a child s skin test comes back positive, even if the child has no signs of TB, the child will probably have to take medication. If not treated, active tuberculosis can be fatal. When treated, tuberculosis can usually be cured. Successful treatment of tuberculosis depends on cooperation between the child, his or her parents and the doctor. Usually, someone needs to watch a child take the medication. A child can t just be given the medication and expect that he or she has taken it. A health care worker watches the child, either in person or sometimes by video. TB treatment consists of taking more than one medication for several months. Medications typically used to treat tuberculosis include isoniazid (INH), rifampin, pyrazinamide, ethambutol or streptomycin. Ethambutol can cause vision changes and is, therefore, not recommended for kids younger than 5. Children with tuberculosis are not as contagious as adults. Within 2 weeks, they are usually not contagious anymore. If a child isn t given the medications as often and for as long as prescribed, the bacteria have a chance to become resistant to the treatment. This is why it is VERY important to follow the doctor s instructions! Prevention There is a tuberculosis vaccine called BCG. BCG prevents the spread of M. tuberculosis in the body, but does not prevent initial infection. BCG vaccine is given to newborn babies in certain areas of the world where TB is prevalent. However, BCG is not recommended for general use in the United States. As with most infectious disease, it is better to prevent tuberculosis than to treat it. Tuberculosis is very preventable. 5
If infected people cover their mouth and nose when coughing or sneezing, the spread of TB can also be prevented. Identifying infected people early and treating them with medications is one of the most effective ways to prevent TB from spreading. The drug INH can prevent TB and should be given to people who have latent tuberculosis are in close contact with infected patients have been in countries where tuberculosis is common are at risk of getting infected with tuberculosis The best way to prevent tuberculosis in children is to treat the adults they are around. Adults with tuberculosis are the most likely source of infection in children. Summary Tuberculosis is a bacterial infection that can be fatal. The body s immune system can usually fight the infection and confine it successfully. When the immune system is weak, confined tuberculosis bacteria can become active and spread to other parts of the body. This is active tuberculosis. Thanks to advances in medicine, treatment is available to treat active TB. It is very important to follow the prescribed treatment. Tuberculosis can be prevented through good hygiene, including good ventilation and covering the mouth when coughing. A vaccine is available for some infants and is recommended for those who live in parts of the world where tuberculosis is a common risk. 6